package com.example.wxapi;


import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

@Controller
@RequestMapping("/wechat/token")
public class WXController {

    public static final String TOKEN = "whyrjj";

    /**
     * 微信Token验证
     *
     * @param signature 微信加密签名
     * @param timestamp 时间戳
     * @param nonce     随机数
     * @param echostr   随机字符串
     * @return
     * @throws NoSuchAlgorithmException
     * @throws IOException
     */
    @RequestMapping("get")
    public void getToken(String signature, String timestamp, String nonce, String echostr, HttpServletResponse response) throws NoSuchAlgorithmException, IOException {
        // 将token、timestamp、nonce三个参数进行字典序排序
        System.out.println("signature:" + signature);
        System.out.println("timestamp:" + timestamp);
        System.out.println("nonce:" + nonce);
        System.out.println("echostr:" + echostr);
        System.out.println("TOKEN:" + TOKEN);
        String[] params = new String[]{TOKEN, timestamp, nonce};
        Arrays.sort(params);
        // 将三个参数字符串拼接成一个字符串进行sha1加密
        String clearText = params[0] + params[1] + params[2];
        String algorithm = "SHA-1";
        String sign = new String(
                org.apache.commons.codec.binary.Hex.encodeHex(MessageDigest.getInstance(algorithm).digest((clearText).getBytes()), true));
        // 开发者获得加密后的字符串可与signature对比，标识该请求来源于微信
        if (signature.equals(sign)) {
            response.getWriter().print(echostr);
        }
    }

}